Bejar R, Curbelo V, Davis C, Gluck L
Obstet Gynecol. 1981 Apr;57(4):479-82.
Human term labor is thought to be initiated by amniotic and chorionic phospholipase A2, an enzyme that liberates arachidonic acid esters from the phospholipids of these membranes, leading to the synthesis of prostaglandins by the placental membranes. The striking association of premature labor with intrauterine infection or contamination, urinary tract infection, and early neonatal sepsis led us to study the microorganisms present in these infections for phospholipase A2 activity. Activity was found in Bacteroides fragilis, Peptostreptococcus, Fusobacterium necrophorum, Streptococcus viridans, Streptococcus fecalis, Streptococcus A and B, Escherichia coli, Klebsiella, Staphylococcus epidermidis, Pneumococcus, Lactobacillus, and Mycoplasma hominis. Bacteroides fragilis, Peptostreptococcus, Fusobacterium, and S viridans had the highest activities. The specific activities of phospholipase A2 from these organisms were several times higher than that of the membrane phospholipase A2 of the amnion and chorion. We postulate that premature labor may be initiated by microorganisms with phospholipase A2 activity from endocervical and/or intrauterine contamination or infection, producing deacylation of arachidonic acid from amniotic phospholipids with increased concentrations of free arachidonic acid and increased prostaglandin synthesis, which triggers labor.
足月分娩被认为是由羊膜和绒毛膜磷脂酶A2启动的，这种酶能从这些膜的磷脂中释放花生四烯酸酯，从而导致胎盘膜合成前列腺素。早产与宫内感染或污染、尿路感染及早期新生儿败血症之间显著的关联促使我们研究这些感染中存在的微生物的磷脂酶A2活性。在脆弱拟杆菌、消化链球菌、坏死梭杆菌、草绿色链球菌、粪链球菌、A组和B组链球菌、大肠杆菌、克雷伯菌、表皮葡萄球菌、肺炎球菌、乳酸杆菌和人型支原体中发现了活性。脆弱拟杆菌、消化链球菌、梭杆菌和草绿色链球菌的活性最高。这些微生物的磷脂酶A2的比活性比羊膜和绒毛膜的膜磷脂酶A2高出几倍。我们推测，早产可能是由来自宫颈内和/或宫内污染或感染的具有磷脂酶A2活性的微生物引发的，这些微生物使羊膜磷脂中的花生四烯酸发生脱酰作用，导致游离花生四烯酸浓度增加和前列腺素合成增加，从而引发分娩。
